Soluble fragments of e-cadherin cell-adhesion molecule increase in urinary-excretion of cancer-patients, potentially indicating its shedding from epithelial tumor-cells

E-cadherin (Ecad) is well known to be a calcium-ion-dependent cell-cell adhesion molecule expressed mostly in epithelial tissues. Previous immunohistochemical studies suggested that this cell adhesion molecule acts as an invasion suppressor and is negligibly detected in cancer metastatic regions. Soluble Ecad fragments derived from the proteolysed membrane-associated form were detected in culture supernatants of two cell lines, COLO 205 and A-431, with normal distribution of cell surface Ecad. Soluble Ecad levels released into culture of COLO 205 exhibiting reduced cell-cell adhesion were apparently elevated above those of A-431 with tight cell-cell adhesion. Furthermore, human circulation and urine continuously contain soluble Ecad which consists mainly of homogeneous 75-85 kDa extracellular domains. Soluble Ecad urinary level per urinary creatinine level was found to be significantly elevated in 53% of patients suffering from various types of cancers including lung, liver, stomach, colon and rectal cancers, as compared with those in the age-matched healthy subjects. These results suggest that dysfunction of cell surface Ecad is responsible for its enhanced proteolytic shedding in tumorigenesis, which may lead to the decrease of cell surface Ecads. Furthermore, excretion of high levels of soluble Ecad fragments potentially indicates the progression of epithelial tumors excessively degrading cell surface Ecad in clinical subjects.

Hydrogen sensing properties of protective-layer-coated single-walled carbon nanotubes with palladium nanoparticle decoration

Protective-layer-coated single-walled carbon nanotubes (SWNTs) with palladium nanoparticle decoration (Pd-SiO(2)-SWNTs) were fabricated and their sensing properties for hydrogen (H(2)) were investigated. SWNTs were coated with a 3-4 nm thick SiO(2) layer by pulsed laser deposition and subsequently decorated with Pd nanoparticles by electron beam evaporation. Even though the SWNTs were completely surrounded by a protective layer, Pd-SiO(2)-SWNTs responded to H(2) down to a concentration of 1 part per million. Compared with the Pd nanoparticle-decorated SWNTs without a protective layer (Pd-SWNTs), Pd-SiO(2)-SWNTs exhibited highly stable sensor responses with variations of less than 20%; Pd-SWNTs showed a variation of 80%. The density of the Pd-SWNTs significantly decreased after the sensing test, while that of the Pd-SiO(2)-SWNTs with the netlike structure remained unchanged. The hydrogen sensing mechanism of the Pd-SiO(2)-SWNTs was attributed to the chemical gating effect on the SWNTs due to dipole layer formation by hydrogen atoms trapped at the Pd-SiO(2) interface. Moreover, the relationship between H(2) concentration and sensor response can be described by the Langmuir isotherm for dissociative adsorption.

Expression of Gene Trios as Predictive Markers of Response to Doxorubicin Based Primary Chemotherapy in Breast Cancer Patients

Some studies have been carried out to identify a gene expression profile predictive of drug response in breast cancer patients and assessed the reproducibility of the model in an independent group of patients. In common, these studies have used the same technique already used to identify the panel of genes in a training set, to verify accuracy of the model in a validation set. We have previously identified through cDNA microarray technology gene trios whose expression was capable of predicting response to neoadjuvant chemotherapy based in doxorubicin and cyclophosphamide in breast cancer patients. We have now evaluated whether expression of these genes analyzed by real time RT-PCR, which represents a more accessible technique, would reproduce cDNA microarray results in separating responsive from non-responsive patients. Twenty eight samples, already studied by cDNA microarray, were analyzed as a technical validation group and subsequently, another 14 samples were evaluated, as a biological validation group. Expression of nine genes (defining five trio combinations, previously identified) was evaluated by RT-PCR in samples from the technical validation group, to define the separating plane, using linear discriminant analysis. Among the five trios, the best separation of tumors was conferred by RPL37A, XLHSRF-1 based trios (with NOTCH1 or NUP210, as third genes), which correctly classified 86% of samples from the technical validation group and 82% in a cross-validation analysis (leave-one-out). Next, samples from the biological validation group were spatially distributed using the pre-established features from these two trios, resulting in 71% correct classification. Additionally, other gene combinations were searched for a higher accuracy in discriminating response and expression of a new trio, RPL37A, SMYD2 and MTSS1, correctly classified 86% and 79% of samples from the technical validation (leave-one-out cross-validation) and the biological validation groups, respectively. Expression values evaluated by cDNA microarray and RT-PCR are reproducible, however they are not exactly the same as these methods are based on different technical principles and normalization approaches. Our data indicate that care should be taken when substituting techniques in an attempt to reproduce a model. In conclusion, expression of the gene trio RPL37A, SMYD2, MTSS1, as evaluated by RT-PCR, is a potential candidate as predictive marker of response to neoadjuvant chemotherapy in breast cancer patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2040.

Transcriptional Profile Changes Induced by Rapamycin in Breast Cancer Maintained in Organ Culture

Background: mTOR (mammalian target of rapamycin) is a serine threonine kinase, member of the AKT/PI3K pathway, which is involved in multiple biologic functions such as transcription, translation, protein degradation and ribosome biogenesis. The activation of this protein results in phosphorilation and activation of S6K1 and 4EBP1. Rapamycin is a potent fungicide, immunossupressive and anti-cancer agent that inhibits the mTOR pathway and is an emerging cancer therapeutic. Objective: The aim of this study was to determine genes regulated by rapamycin in samples of ductal invasive breast cancer to identify novel markers of rapamycin response. Material and Methods: Inhibition of some elements of AKT pathway was assessed by immunohistochemistry in samples of breast carcinoma maintained in organ culture of fresh cut slices that preserves the interaction between epithelium and stroma before and after treatment with rapamycin. Additionally changes of the gene expression profile was analyzed by microarray in these samples subdivided in positive and negative Erb-B2. Results: Immunohistochemistry analysis indicated a significant decrease of 4EBP1 in the samples of tumor treated with rapamycin compared with the control cases. Microarray analysis revealed that few common genes were regulated in both tumor types but rapamycin affected the expression of genes mainly involved in cellular transcription and translation in both groups. To confirm the results obtained through microarray technique, RT-PCR analysis was performed in independent samples and we validated the genes WWOX, EXT1 and GTF2E2 in 60% of our cases. Over expression of the autophagy related beclin 1 indicated a contribution of autophagy to cytotoxicity of rapamycin. Conclusion: The organ culture represents a simple method to determine the effects of rapamycin and using gene profile analysis, novel genes that possible could be used as markers of mTOR inhibition were identified. Supported by FAPESP nº 04/04607-8

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6129.

Breast Cancer Gene Expression Profile in Post-Menopausal Patients Supplemented with Vitamin D

Vitamin D supplementation is indicated for post-menopausal women to prevent osteoporosis and lower 25(OH)2D3 or 1,25(OH)2D3 serum levels have been associated with breast cancer incidence or prognosis (metastasis). The antiproliferative effects of vitamin D are observed in breast cancer cell lines exposed to phamacological doses of calcitriol (1,25(OH)2D3, 100nM) but whether physiological doses are sufficient to produce growth inhibition in vivo is not known. The aim of our study was to investigate gene expression profile changes of breast cancer samples from patients supplemented with calcitriol, presenting an anti-proliferative effect on the tumor. Post-menopausal women diagnosed with breast cancer were instructed to take one (0.25ug/day, n=8) or two (0.50ug/day, n=8) tablets of calcitriol after tumor biopsy. Median time of supplementation was 30 days. Sixteen tumor samples were collected during biopsy (before supplementation) and breast surgery (after supplementation). Proliferation index was evaluated by tumor Ki-67 immunohistochemistry (IHC) expression in breast cancer samples before and after calcitirol supplementation and 1000 cells were counted by three observers (p < 0,001, Pearson's correlation). After establishing a counting error between observers, the cut-off value was fixed in 26.53% (percentile 60%) to define response. Patients were then categorized as responsive (a reduction of more than 26.53% on positive Ki-67 positive cells) and non-responsive (difference between samples before and after supplementation not exceeding 26.53%). Among our sixteen patients, all were categorized as responsive to calcitriol supplementation except for two. So far, gene expression profile of two patients (both categorized as responsive) has been analyzed using the U133 Plus 2.0 Affymetrix Gene Chips from 100ng of total RNA. To verify signalling pathways possibly involved in response to vitamin D exposure, additional five samples from a parallel study, in which breast cancer samples from post menopausal patients were collected at surgery and treated in vitro with a low concentration of calcitriol, 0.5nM (that can be attained with subcutaneous administration of doses of 8ug calcitriol, without hypercalcemia) for 24h, were included in the analysis. All samples had RNA hybridized to the same gene chips. Results were normalized and analyzed using RMA and Mev.TM4 softwares. CYP24A1, a target gene of vitamin D, presented a positive regulation after calcitriol supplementation in all samples analyzed. Differentially expressed genes were involved in the regulation of cell cycle [SMAD2, cyclin E, YWHAQ (14-3-3 family] and calcium signalling (HTR7, PTGER1 and PTGER2). Our results indicate that the tumor proliferation index is reduced upon calcitriol supplementation. Moreover, potentially regulated pathways in breast cancer specimens after administration of low doses of calcitriol are regulation of cell cycle and calcium signaling.Supported by FAPESP 2007/01111-0 – 2007/04799-2

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6128.

Differential Gene Expression Profiles in Breast Cancer Tumors from Young and Post-Menopausal Patients

Breast cancer in young patients (<35 yrs) has been hypothesized to be more histologically aggressive than those occurring in older cohorts, based mainly in their histopahtological features and worse prognosis. Our current knowledge of the genes involved in such differences is limited. To obtain insight into the molecular processes underlying tumorigenesis in young women we have used 44K cDNA microarrays (Agilent) to compare the gene expression profiles of 30 samples obtained from patients younger than 35 years (median 32,5, range 25-35) and 19 post-menopausal patients (median 66, range 55-88 ), all of them with ductal invasive carcinoma. Both age groups showed similar incidence of ER and PR-positive cases (70 and 60%, respectively). We considered as differentially expressed genes those presenting a p value below 0.01(t test) and fold variation of+/- 2.5.Gene ontology was performed using the GOTree machine tool (GOTM). By such criteria, 121 genes (86% down-regulated) were identified between the two groups here analyzed. In tumors arising in younger women we found an overrepresentation of genes involved with G-protein receptor signaling,cytoskeleton and muscle development, including ankyrin 3,filamin B, gfsarcoglycan and small proline- rich protein, one of the cornified-envelope structural precursor protein. In addition, solely in the younger women set we compared the gene profiles between women with (n =19) or without (n = 10) familial history of breast carcinoma. Using the same criteria, 59 transcripts distinguished the two subsets: GO categories over represented in tumors from patients with familial history included cell-cell adhesion, cytoskeleton organization,cell motility and protein binding related genes. These results indicate that breast cancer tumors arising in young women, besides their uniqueness regarding tumorigenesis, also differ among familial and non-familial cases as revealed by gene expression profiles.Support: FAPESP 04/14029-1

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6138.

Gadolinium-enhanced three-dimensional magnetization-prepared rapid gradient-echo (3D MP-RAGE) imaging is superior to spin-echo imaging in delineating brain metastases

BACKGROUND

Precisely defining the number and location of brain metastases is very important for establishing a treatment strategy for malignancies. Although magnetic resonance imaging (MRI) is now considered the best modality, various improvements in sequences are still being made.

PURPOSE

To prospectively compare the diagnostic ability of three-dimensional, magnetization-prepared rapid gradient-echo (3D MP-RAGE) imaging in detecting metastatic brain tumors, with that of two-dimensional spin-echo (2D SE) T1-weighted imaging.

MATERIAL AND METHODS

A total of 123 examinations were included in this study, and 119 examinations from 88 patients with known malignancies were analyzed. All patients underwent T1- and T2-weighted 2D SE transverse imaging, followed by gadolinium-enhanced T1-weighted transverse and coronal 2D SE imaging and 3D MP-RAGE transverse imaging. Four radiologists interpreted the images to compare the accuracy and the time required for interpretation for each imaging.

RESULTS

3D MP-RAGE imaging was significantly better than 2D SE imaging for detecting metastatic brain lesions, regardless of the readers' experience. The sensitivities of the 3D MP-RAGE and 2D SE imaging for all observers were 0.81 vs. 0.80 (P>0.05), specificities were 0.93 vs. 0.87 (P<0.05), positive predictive values were 0.92 vs. 0.86 (P<0.05), negative predictive values were 0.78 vs. 0.75 (P>0.05), and accuracies were 0.84 vs. 0.78 (P<0.05), respectively. There was no significant difference in the time required for image interpretation between the two modalities (15.6+/-4.0 vs. 15.4+/-4.1 min).

CONCLUSION

3D MP-RAGE imaging proved superior to 2D SE imaging in the detection of brain metastases.

Utilization of okara, a byproduct from soymilk production, through the development of soy-based snack food

This study was conducted to develop a new soy-based food product that could utilize okara (a byproduct from soymilk production) and maximize the health benefits of okara for the consumer. A Japanese commercial okara snack product was used as a standard reference. Two types of dried okara powder, a commercially dried okara powder with 7.7% moisture content made from regular (lipoxygenase-present) soybeans and a partially dried okara with 44.3% moisture content made from lipoxygenase-free (LOX-null) soybeans, were used in this study. Commercial low saturated soybean oil and commercial low linolenic acid soybean oil were also used in the same formulation to compare and find the best formulation for a baked or deep-fat-fried soy-based food product. Two descriptive analysis studies were performed with a minimum of 15 trained panelists. Instrumental analyses with a Hunter Lab system and a TA.XT2i texture analyzer and chemical analysis were performed to compare with the sensory results. All the results were statistically analyzed. The baked product made from commercial low saturated soybean oil and the partially dried LOX-null okara powder gave the closest flavor, texture, and appearance to the reference standard. The final product contained 11.4% protein and 7.4% dietary fiber, which were, respectively, 1.5 and 2.0 times higher than the reference. The calcium content was also 4.3 times higher than the reference. The objectives of this study were achieved by developing a new soy-based snack food, which has more health benefits with an enjoyable flavor and texture than the existing commercial product.

Utilization of soybeans and their components through the development of textured soy protein foods

Textured soy protein (TSP), an extruded and fibrous-structured product, is mainly used as meat analog or extender. Meat alternatives are third in sales in the U.S. soy food marketplace. A primary problem that limits the incorporation of more TSP into products is the undesirable "beany" flavor. The objective of this study was to develop the best formulation of TSP and vegetable-based flavors to produce consumer acceptable "chicken" or "shrimp" flavored TSP using heat application processes. Four different types of commercial TSP (containing an average of 51% protein) strip-shaped extruded with a narrow die (STRIP-N) or with a wider die (STRIP-W), shred-shaped (SHRED) strips, and 1-cm crouton-shaped bits (BITs) were used. The TSPs were baked or deep-fat fried after soaking in 5 different commercial vegetable-based powered, liquid, or oil-based flavors ranged from 0% to 22.3% concentrations. Four descriptive analyses with a minimum of 14 trained panelists were utilized to evaluate the attributes of the finished TSP. Proximate, color, and texture analyses were performed on each TSP product. All treatments were statistically analyzed. Both instrumental and sensory tests demonstrated that BIT had a significantly higher crispness than other TSP. The powder type of chicken flavor used for a consumer panel had a more intense flavor than others with the optimum hydration time, 15 min. A consumer test with 125 people was performed with the highest chicken flavored (22.3%) fried and baked BIT. Overall, 66% of the total consumers preferred the fried BIT to the baked BIT, and 31% preferred the baked BIT.

105 THE Oct4/Cdx2 EXPRESSION AND CELL FATE OF INDIVIDUAL TWO-CELL BLASTOMERES IN TWO MOUSE STRAINS

Fertile adults and occasionally twins have been derived from murine blastomeres at the 2-cell stage, indicating that such blastomeres may be equivalently totipotent, but there are conflicting reports that individual blastomeres from 2-cell stage murine conceptuses make different contributions to the embryonic and abembryonic regions of the blastocyst, implying that they differ in developmental potential. Here, we have re-examined this subject using 2 mouse strains, CF1 and NIH Swiss (SW), and 2 experimental approaches, random blastomere destruction at the 2-cell stage by repeated insertion of a needle into its nucleus and lineage tracing with the dye, DiI-CM. The manipulated conceptuses and untreated controls were cultured in KSOM-AA to morula and blastocyst stages (84 or 108 h pc, respectively), fixed, and immunostained for Oct4 and Cdx2. Antigen distribution, number of nuclei (stained by 42,6-diamidino-2-phenylindole), and cell progeny labeled with DiI-CM were examined by confocal laser scanning microscopy. Cell numbers are means � SD and were analyzed by a Student t-test. Cells positive for Cdx2 were assumed to represent trophectoderm or trophectoderm precursors, ones positive for Oct4 but negative for Cdx2 (Oct+Cdx–) inner cell mass. Ablation of a blastomere failed to prevent developmental progression in either strain, but the total number of cells at both morula (SW 11.4 � 3.3 v. 19.2 � 7.1; CF1 10.1 � 2.5 v. 22.1 � 6.4) and blastocyst (SW 48.6 � 7.4 v. 69.4 � 9.9; CF1 24.8 � 6.2 v. 53.8 � 13.5) was significantly reduced. In SW, the average fraction of Oct+Cdx– cells after blastomere ablation was significantly lower (P < 0.05) than in controls in morulae (0.47 � 0.2 v. 0.65 � 0.1) but not in blastocysts (0.33 � 0.1 and 0.34 � 0.1). In CF1, the fraction of Oct+Cdx– cells was lower (P < 0.05) than controls in both morulae and blastocysts (0.31 � 0.2 v. 0.58 � 0.2 and 0.18 � 0.1 v. 0.27 � 0.04, respectively). The CF1 morulae fell mainly into 2 groups, one low fraction (≤0.3, 54%) of Oct+Cdx– cells and the other with a more normal fraction (0.3 to 0.8, 43%) relative to controls. A majority of NIH Swiss morulae had an Oct+Cdx– cell fraction >0.4 and in this respect resembled controls. We then examined these strain differences by lineage tracing. The majority of SW blastocysts (65%, n = 34) demonstrated a random localization of DiI-labeled cell progeny (i.e., there was no preferential distribution of labeled cells to either the embryonic or abembryonic poles). By contrast, in CF1 (n = 38), 32% of blastocysts had labeled cells confined to their embryonic end and 42% with DiI-labeled, Cdx2-positive cells clustered at the abembryonic locale. A random localization was observed in 26% of blastocysts. In conclusion, these data confirm that there is plasticity in early mouse development but also suggest that in CF1, but not in SW conceptuses, blastomeres at the 2-cell stage differ in their abilities to contribute to the embryonic pole. Similar strain differences may explain the disagreements among studies on lineage tracing in early cleavage stage conceptuses.

Modification of the hepatic mitochondrial proteome in response to ischemic preconditioning following ischemia-reperfusion injury of the rat liver

BACKGROUND/AIM

Ischemic preconditioning (IPC) may reduce hepatic ischemia-reperfusion (IR) injury, but efficacy of IPC on mitochondrial proteome is not demonstrated. We investigated how IPC modifies the mitochondrial proteome after IR injury.

METHODS

Rats were subjected to 25 min of portal triad crossclamping (IR group, n = 8). In the IPC group (n = 8), 10 min of temporal portal triad clamping was performed before 25 min of portal clamping. Samples were obtained after 24 h. The mitochondrial inner-membrane potential was measured by the uptake of a lipophilic cationic carbocyanine probe and mitochondrial proteome was also investigated using 2-dimensional differential in-gel electrophoresis and liquid chromatography-tandem mass spectrometry.

RESULTS

Mitochondrial inner-membrane potential and glutathione were lower and serum transaminase was higher in the IPC group than in the IR group. The mitochondrial precursor of aldehyde dehydrogenase 2 and alpha-methylacyl-CoA-racemase were upregulated in the IPC group in comparison to the IR group. In contrast, protein disulfide-isomerase A3 precursor, 60S acid ribosomal protein P0, carbonic anhydrase 3 and superoxide dismutase were significantly more downregulated in the IPC group than in the IR group.

CONCLUSIONS

A hepatoprotective effect by IPC was not shown; however, IPC caused significant up- or downregulation of several mitochondrial proteins.

Effect of prenatal exposure to bisphenol A on the serum testosterone concentration of rats at birth

In the rat, testosterone (T) in the neonatal period plays an important role in sexual differentiation and there is a serum T surge in male rats 2 hours after birth. Pregnant female rats were exposed to various doses of bisphenol A (BPA) from gestational day 1 (GD1) through 2 hours after parturition. About half of the BPA-exposed and control dams were subjected to cesarean section on GD22. The male fetuses on GD22 were immediately sacrificed and blood was collected. The other half of the BPA-treated and control dams delivered at GD23 (parturition day). The male pups were sacrificed 2 hours after birth. Serum T concentration was determined by radioimmunoassay (RIA). The BPA concentration in the fetal serum on GD22 increased inversely to the T levels in the serum. The T concentration in the pups' serum 2 hours after birth decreased inversely to the BPA concentration in the serum. However, there were no differences in the serum T concentration among the various doses of BPA. These results suggest that exposure to BPA in utero inhibits the T surge in the neonatal period and we speculate that exposure to BPA in utero disrupts the endocrine environment in the neonatal male.

Systematic identification for inert region of a brain from EEG

Evaluation of biomedical signals is important in the diagnosis of neurology diseases, such as dementia, in neurology through the use of electroencephalograms (EEG). While automated techniques exist for EEG analysis, it is likely that additional information can be extracted from EEG signal through the use of new methods. We describe a method for identifying inert region from EEG. This method uses EEG as input to an artificial neural network with five outputs: activity in whole regoin and inert region separated by four regions.

High-yield synthesis of conductive carbon nanotube tips for multiprobe scanning tunneling microscope

We have established a fabrication process for conductive carbon nanotube (CNT) tips for multiprobe scanning tunneling microscope (STM) with high yield. This was achieved, first, by attaching a CNT at the apex of a supporting W tip by a dielectrophoresis method, second, by reinforcing the adhesion between the CNT and the W tip by electron beam deposition of hydrocarbon and subsequent heating, and finally by wholly coating it with a thin metal layer by pulsed laser deposition. More than 90% of the CNT tips survived after long-distance transportation in air, indicating the practical durability of the CNT tips. The shape of the CNT tip did not change even after making contact with another metal tip more than 100 times repeatedly, which evidenced its mechanical robustness. We exploited the CNT tips for the electronic transport measurement by a four-terminal method in a multiprobe STM, in which the PtIr-coated CNT portion of the tip exhibited diffusive transport with a low resistivity of 1.8 kOmega/microm. The contact resistance at the junction between the CNT and the supporting W tip was estimated to be less than 0.7 kOmega. We confirmed that the PtIr thin layer remained at the CNT-W junction portion after excess current passed through, although the PtIr layer was peeled off on the CNT to aggregate into particles, which was likely due to electromigration or a thermally activated diffusion process. These results indicate that the CNT tips fabricated by our recipe possess high reliability and reproducibility sufficient for multiprobe STM measurements.

Measurement of Radical-Scavenging Ability in Small Bowel Ischemia/Reperfusion Injury in Rats Using an In Vivo and Ex Vivo Electron Paramagnetic Resonance Technique

Reperfusion of ischemic tissues results in the formation of toxic reactive oxygen species (ROS), such as superoxide anion, hydroxyl radicals, hydroperoxide, and peroxynitrite. ROS are potent oxidizing agents, fully capable of damaging cellular membranes by lipid peroxidation. In this study, we applied for the first time the in vivo electron paramagnetic resonance (EPR)/spin probe and ex vivo EPR technique to provide direct evidence of ROS following experimentally induced small bowel ischemia/reperfusion (I/R) injury. The decay rate (spin clearance rate) was determined over the first 3 minutes at 6 hours after reperfusion. Decay rates in rats subjected to I/R injury were lower than those in the sham group. Superoxide scavenging activity (SSA) in rats subjected to I/R injury was significantly lower than that in the sham group. In conclusion, this study demonstrated that it is possible to detect the accumulation of ROS following experimentally induced small intestine I/R injury using an in vivo and an ex vivo EPR technique with a spin probe.

Glomus jugulare tumor presenting with intracerebellar hemorrhage

What is believed to be the first case of a glomus jugulare tumor presenting with intracerebellar hemorrhage is described. A 25-year-old normotensive man suddenly suffered from severe headache, nausea, vomiting, vertigo, and ataxia due to an intracerebellar hemorrhage. Magnetic resonance imaging and angiography revealed a highly vascular jugulare foramen tumor extending into the intracranial space adjacent to the hematoma. Total removal of the tumor was performed successfully via the combined pre- and retrosigmoid approach, and the histologic diagnosis was a glomus jugulare tumor. We concluded that one of the numerous draining veins on the surface of intracranial tumor, which were observed during the operation, was the origin of the intracerebellar hemorrhage.

DNA damaging agent-induced autophagy produces a cytoprotective adenosine triphosphate surge in malignant glioma cells

Although autophagy enhances cell survival in nutrient-deprived cells by increasing adenosine triphosphate (ATP) production, it remains unclear if autophagy functions similarly in cells treated with cytotoxic chemotherapy agents. To address this issue, we measured both the ability of DNA damaging agents (Temozolomide, and Etoposide) to induce an autophagy-dependent production of ATP, and the effects of modulation of autophagy on drug-induced cell death. Both drugs induced an autophagy-associated increase in ATP production in multiple glioma cell lines. The drug-induced ATP surge could not be blocked by glucose starvation, but could be blocked by preincubation with the autophagy inhibitor 3-methyladenine (3-MA), an siRNA targeting beclin 1, or the mitochondrial inhibitor oligomycin. Inhibition of autophagy-induced ATP production increased non-apoptotic cell death associated with micronucleation, while restoration of the 3-MA-inhibited ATP surge by addition of pyruvate suppressed cell death. These results show that DNA damaging agents induce an autophagy-associated ATP surge that protects cells and may contribute to drug resistance.